How do you know Macbeth is Paranoia?

Macbeth is paranoid of all kinds of things. He is scared he'll be discovered, he is scared he's going to hell.....In Act 4 the Apparition tells Macbeth that to be beware of MacDuff. Then the second apparition states nobody born from a woman will ever harm Macbeth. Macbeth figures he will make sure he does away with Macduff anyway.

"Then live, Macduff. What need I fear of thee?

But yet I’ll make assurance double sure,

And take a bond of fate. Thou shalt not live,

That I may tell pale-hearted fear it lies,

And sleep in spite of thunder." (Act 4)